One problem with implanted sensor systems is that, within a certain time after implantation in the body, they are recognized as foreign bodies and encapsulated, and are thus decoupled from the body fluids. As a result of this decoupling, the functional contact between the body fluid and the sensor system is adversely affected, and may even be interrupted.
The first step in the encapsulation generally consists of the agglomeration of autologous material at the surface of the implanted sensor system. On the basis of the agglomeration of autologous material which has occurred, this is followed by overgrowth and inclusion of the sensor system by connective tissue cells (see James M. Anderson, Analiz Rodriguez, and David T. Chang: Foreign body reaction to biomaterials;
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WX3-4RFD6BC-1&_user=7184476&_coverDate=04%2F30%2F2008&_rdoc=1&_fmt=high&_orig=search&_sor t=d&_docanchor=&view=c&_searchStrId=1357446928&_rerunOrigin=scholar.google&_acct=C000061852&_version=1&_urlVersion=0&_userid=7184476&md5=eea57f7c8097bcb0c50f6f9 743f34f58-aff2 Seminars in Immunology, Volume 20, Issue 2, April 2008, pages 86-100, Innate and Adaptive Immune Responses in Tissue Engineering).
Approaches are currently known which are directed to extending the service life of implanted sensor systems. Thus, for example, there are sensor systems which have a plurality of independent sensors configured in a sensor array, and the individual sensors are enabled over time in a coordinated manner during operation of the sensor system. Thus, in this approach, the encapsulation is not directly prevented; instead, after encapsulation of a first sensor of the sensor system occurs, another sensor which is not encapsulated is simply placed in operation. One problem with this approach is that due to their nature, these sensor systems must have a relatively large and complex design since they must accommodate multiple sensors for sequential operation. Besides the space requirements, this also results in significant additional costs.
Alternatively, coatings have been proposed which are designed to selectively suppress or interfere with certain biochemical processes of the agglomeration reactions and processes. However, these coatings usually interact with only one specific step or a few selected steps of the encapsulation process. Since encapsulation may occur via different or alternative processes or process steps, the extent of the influence which is achieved is usually limited. However, encapsulation generally occurs after an initial delay, thus limiting the service life of the sensor system.
The present invention is directed at overcoming one or more of the above-identified problems.